Subject: [PATCH/RFC v2] ARM: amba: Remove AMBA level regulator support

From: [email-masked] (Rob Herring)
Date: Fri, 06 Apr 2012 13:12:27 -0500

On 04/01/2012 01:58 PM, Mark Brown wrote:
> The AMBA bus regulator support is being used to model on/off switches
> for power domains which isn't terribly idiomatic for modern kernels with
> the generic power domain code and creates integration problems on platforms
> which don't use regulators for their power domains as it's hard to tell
> the difference between a regulator that is needed but failed to be provided
> and one that isn't supposed to be there (though DT does make that easier).
> 
> Platforms that wish to use the regulator API to manage their power domains
> can indirect via the power domain interface.
> 
> This feature is only used with the vape supply of the db8500 PRCMU
> driver which supplies the UARTs and MMC controllers, none of which have
> support for managing vcore at runtime in mainline (only pl022 SPI
> controller does).  Update that supply to have an always_on constraint
> until the power domain support for the system is updated so that it is
> enabled for these users, this is likely to have no impact on practical
> systems as probably at least one of these devices will be active and
> cause AMBA to hold the supply on anyway.
> 
> Signed-off-by: Mark Brown <[email-masked]>
> ---

This and pl011 fixes are needed to get highbank working with 3.4, so:

Tested-by: Rob Herring <[email-masked]>

Rob

> 
> Updated to add the always_on constraint for db8500-prcmu as discussed in
> the changelog.
> 
>  drivers/amba/bus.c         |   42 +-----------------------------------------
>  drivers/mfd/db8500-prcmu.c |    1 +
>  drivers/spi/spi-pl022.c    |    2 --
>  include/linux/amba/bus.h   |    8 --------
>  4 files changed, 2 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index 01c2cf4..cc27322 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -247,8 +247,7 @@ static int amba_pm_restore(struct device *dev)
>  /*
>   * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
>   * enable/disable the bus clock at runtime PM suspend/resume as this
> - * does not result in loss of context.  However, disabling vcore power
> - * would do, so we leave that to the driver.
> + * does not result in loss of context.
>   */
>  static int amba_pm_runtime_suspend(struct device *dev)
>  {
> @@ -354,39 +353,6 @@ static void amba_put_disable_pclk(struct amba_device *pcdev)
>  	clk_put(pclk);
>  }
>  
> -static int amba_get_enable_vcore(struct amba_device *pcdev)
> -{
> -	struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
> -	int ret;
> -
> -	pcdev->vcore = vcore;
> -
> -	if (IS_ERR(vcore)) {
> -		/* It is OK not to supply a vcore regulator */
> -		if (PTR_ERR(vcore) == -ENODEV)
> -			return 0;
> -		return PTR_ERR(vcore);
> -	}
> -
> -	ret = regulator_enable(vcore);
> -	if (ret) {
> -		regulator_put(vcore);
> -		pcdev->vcore = ERR_PTR(-ENODEV);
> -	}
> -
> -	return ret;
> -}
> -
> -static void amba_put_disable_vcore(struct amba_device *pcdev)
> -{
> -	struct regulator *vcore = pcdev->vcore;
> -
> -	if (!IS_ERR(vcore)) {
> -		regulator_disable(vcore);
> -		regulator_put(vcore);
> -	}
> -}
> -
>  /*
>   * These are the device model conversion veneers; they convert the
>   * device model structures to our more specific structures.
> @@ -399,10 +365,6 @@ static int amba_probe(struct device *dev)
>  	int ret;
>  
>  	do {
> -		ret = amba_get_enable_vcore(pcdev);
> -		if (ret)
> -			break;
> -
>  		ret = amba_get_enable_pclk(pcdev);
>  		if (ret)
>  			break;
> @@ -420,7 +382,6 @@ static int amba_probe(struct device *dev)
>  		pm_runtime_put_noidle(dev);
>  
>  		amba_put_disable_pclk(pcdev);
> -		amba_put_disable_vcore(pcdev);
>  	} while (0);
>  
>  	return ret;
> @@ -442,7 +403,6 @@ static int amba_remove(struct device *dev)
>  	pm_runtime_put_noidle(dev);
>  
>  	amba_put_disable_pclk(pcdev);
> -	amba_put_disable_vcore(pcdev);
>  
>  	return ret;
>  }
> diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
> index ebc1e86..5be3248 100644
> --- a/drivers/mfd/db8500-prcmu.c
> +++ b/drivers/mfd/db8500-prcmu.c
> @@ -2788,6 +2788,7 @@ static struct regulator_init_data db8500_regulators[DB8500_NUM_REGULATORS] = {
>  		.constraints = {
>  			.name = "db8500-vape",
>  			.valid_ops_mask = REGULATOR_CHANGE_STATUS,
> +			.always_on = true,
>  		},
>  		.consumer_supplies = db8500_vape_consumers,
>  		.num_consumer_supplies = ARRAY_SIZE(db8500_vape_consumers),
> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 96f0da6..09c925a 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -2195,7 +2195,6 @@ static int pl022_runtime_suspend(struct device *dev)
>  	struct pl022 *pl022 = dev_get_drvdata(dev);
>  
>  	clk_disable(pl022->clk);
> -	amba_vcore_disable(pl022->adev);
>  
>  	return 0;
>  }
> @@ -2204,7 +2203,6 @@ static int pl022_runtime_resume(struct device *dev)
>  {
>  	struct pl022 *pl022 = dev_get_drvdata(dev);
>  
> -	amba_vcore_enable(pl022->adev);
>  	clk_enable(pl022->clk);
>  
>  	return 0;
> diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
> index 7847e19..63a59ac 100644
> --- a/include/linux/amba/bus.h
> +++ b/include/linux/amba/bus.h
> @@ -19,7 +19,6 @@
>  #include <linux/mod_devicetable.h>
>  #include <linux/err.h>
>  #include <linux/resource.h>
> -#include <linux/regulator/consumer.h>
>  
>  #define AMBA_NR_IRQS	2
>  #define AMBA_CID	0xb105f00d
> @@ -30,7 +29,6 @@ struct amba_device {
>  	struct device		dev;
>  	struct resource		res;
>  	struct clk		*pclk;
> -	struct regulator	*vcore;
>  	u64			dma_mask;
>  	unsigned int		periphid;
>  	unsigned int		irq[AMBA_NR_IRQS];
> @@ -75,12 +73,6 @@ void amba_release_regions(struct amba_device *);
>  #define amba_pclk_disable(d)	\
>  	do { if (!IS_ERR((d)->pclk)) clk_disable((d)->pclk); } while (0)
>  
> -#define amba_vcore_enable(d)	\
> -	(IS_ERR((d)->vcore) ? 0 : regulator_enable((d)->vcore))
> -
> -#define amba_vcore_disable(d)	\
> -	do { if (!IS_ERR((d)->vcore)) regulator_disable((d)->vcore); } while (0)
> -
>  /* Some drivers don't use the struct amba_device */
>  #define AMBA_CONFIG_BITS(a) (((a) >> 24) & 0xff)
>  #define AMBA_REV_BITS(a) (((a) >> 20) & 0x0f)